Open AccessReaction of N ‐(3‐Pyrene)maleimide with Thiol Groups of Reticulocyte Ribosomes
Author(s) -
LEE Terry,
HEINTZ Roger L.
Publication year - 1976
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1976.tb10430.x
Subject(s) - maleimide , pyrene , thiol , derivatization , chemistry , reticulocyte , ribosomal protein , ribosome , ribosomal rna , stereochemistry , biochemistry , organic chemistry , high performance liquid chromatography , rna , gene
The reaction of N–(3–pyrene)maleimide with thiol groups of rabbit reticulocyte ribosomes offers a possible fluorescent probe for studying ribosomal structure and conformation. At relatively low concentrations of N–(3–pyrene)maleimide a group of 30–40 readily reactive sulfhydryl residues is derivatized. The major ribosomal proteins containing these thiol groups are identified as S2+S3, S5, S7, S8, S29, S31, S32, L1, L5, L6, L10+L14, L15, L18+L19, and L36. Ribosomal activity, as measured by the nonenzymic binding of phenylalanyl‐tRNA and polyphenylalanine synthesis, is inhibited by this degree of reaction with N–(3–pyrene)maleimide. This inhibition is relieved by the prior binding of polyuridylic acid to the ribosomes while the extent of derivatization by N–(3–pyrene) maleimide is diminished only slightly. The average relative polarization of the fluorescence of the ribosomal bound N–(3–pyrene)maleimide changes significantly with the degree of derivatization of ribosomal thiol groups or with the binding of polyuridylic acid, indicating the value of such a fluorescent thiol‐derivatizing agent as a probe of ribosomal structure.